釋氏要覽 2.33

2.33

The Five-Part Vinaya says: There were resident monks who did not bow to visiting monks, and visiting monks who did not bow to resident monks. A monk arrived at a monastery and did not bow to the long-resident monks. A long-resident monk asked, "Where have you come from? We should know that the monks of your place are all arrogant like this." They reported this to the Buddha. The Buddha said, "You should bow to all. Those who do not bow commit a duṣkṛta offense."